Composite gear.



C. H. CALKINSL COMPOSITE GEAR.

APPLICATION FILED AUG.8. I916.

1,2125%, Patented. Jamlmmz I I I 1 -15 I I I I I I I l I I I I BY p MM4@ATTORNEY v l v eluding various kinds of iron and steel) or CHARLES H. CA-LKINS, or humou amass,Aoiarcsnr'rs, ASSIGNOR roinat'srr acrame TOOL oomranr, a coaroaarrow or massaennsarrs.

ooiarosirii GEAR.

Specification of Letters Patent. yg afi gntgflg 16. 1911?;

Application r'lled August 8, 1916. Serial No. 14.32218;

i To all whom itmay concern:

Beit known that I, GHARLES" CALKms, a citizenof the United Statearesidi'ng in Ludlow, Massachusetts, have invented certam new and useful Improvements'm Gomposite- Gears, of which the following is -a specification.

v In my application for Patent No. 85,809, filed Marchv 22, 1916, I-have described a worm gear. made with a center ofiron (insimilar comparatively strong metal and with teeth of, comparatively weak anti-friction material, such as bronze, and ham shown" several styles ofconstruction and presented genric claims thereon. "The present application is based on another style ofconstruc- Fig. 2 is a radial section of the outer portionthereof; Fig. 3 is a face elevation of before the outer ring is applied,

tion of such acomposite gear.

The accompanying drawings illustrate an embodiment of the inventio I .Figure 1 is a side elevation of a gear;

the center,

thereto. Referring now to the embodiment ofthe invention illustrated the part marked A is the center, of cast iron. This is formed with an annular groove B around its face, the sides of which constitute undercut shoulders C. A number of holes D are formed inthe iron center extending substantially or approximately toward the. axis of the Wheel and preferably,'though not necessarily, extending through the rim of the center. They.

. may'be formed in the casting of the center or by drilling or otherwise. A bronze ring E is cast in the groove B, and, inthe pourf is curved outward at its side edges as shown ing, projections F of the bronze ring enter the holes D. The rim of the cast iron center in Fig. 2 and the holes D are approximately normal to the faces of the rim so that they ,provide a firm an'chor'for the bronze r ng against outward movement of the latter,

similar to the anchor provided by the overhang of the shoulder C. In addition the engagement of the bronze ring with the holes D provides an anchor against circumferential movement ofthe bronze ring on the iron center. The bronze ring 18 thus firmly held, in engagement with the iron center so for the same strengti in the other to that teeth G may be cut therein in the usual Way and of any. desired shape, either worm gears, spur gears, spiral'gears or otherstyle.

his construction is extremely simple to make. There is aconsi derable saving of expense as compared with solid bronze gear and an increased strength at the center for a wheel of given' weight; or a lighter wheel eration isrsufficient to form the bronze ring in the annular groove in the iron center and to anchor it'firmly in place. in making this composite casting the iron center will first Y A single casting opbe cast in the usual way. This will then be pla'cedin a mold and the bronze poured in place around it, preferablyheating the cast iron before pouring the bronze. A number of slots are provided around one of the overhanging shoulders of the iron center for permitting theescape of'air which might be imprisoned. The projections on the bronze ring entering the holes in the center constitute .in effect .a bolted 'cori'structiom. which takes care of any looseness which.

might exist between thetwo parts under considerable variations of temperature ow ing'to the difference between the coefiicients 1' of expansion of the two materials. hat I claim is 2-. 1. A gear having a center of tively weakanti-friction material formed vin a ring of such material extending around comparetively strongmetal and teeth. of compara-f 2. A gear 'having a center. of comparatively strong metal with an annular shoulder on its outer face and a cast ring of comparatively weak anti-friction material on said center in engagement with said shoulder, one of said parts having also -projections entering openings in tlie other and extending toward the axis.

3.1a gear having a center of comparativel-y strong metal with an annular groove ice in its outer face, and a ring of compara-' tively weak anti-friction material cast in said groove, said center having also. (mam emme extending toward the axis and. said and with projections enteringthe holes in the ting projections cast therewith and rim of the cast iron center, so as to firmly said openings. anchor the bronze ring on the castiron cen- 1G 2111" having a center A of east iron ter, said rim having teeth vcut therein.

1. 11112111131 roove B extending around. In Witness whereof I have hereunto hereof and with holes in said rim signed my name.

onze ring E cast in said greove CHARLES H. CALKINS. 

